US3712811A - Electrophotographic material - Google Patents

Electrophotographic material Download PDF

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US3712811A
US3712811A US00121508A US3712811DA US3712811A US 3712811 A US3712811 A US 3712811A US 00121508 A US00121508 A US 00121508A US 3712811D A US3712811D A US 3712811DA US 3712811 A US3712811 A US 3712811A
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Prior art keywords
phenyl
methyl
perchlorate
benzopyranylidene
solution
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US00121508A
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Y Murakami
Y Hasegawa
K Morimoto
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Panasonic Holdings Corp
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Matsushita Electric Industrial Co Ltd
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Priority claimed from JP2176770A external-priority patent/JPS4843152B1/ja
Priority claimed from JP2176670A external-priority patent/JPS4843151B1/ja
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0664—Dyes
    • G03G5/0666—Dyes containing a methine or polymethine group
    • G03G5/0668—Dyes containing a methine or polymethine group containing only one methine or polymethine group
    • G03G5/067—Dyes containing a methine or polymethine group containing only one methine or polymethine group containing hetero rings
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0622—Heterocyclic compounds
    • G03G5/0644—Heterocyclic compounds containing two or more hetero rings
    • G03G5/0661—Heterocyclic compounds containing two or more hetero rings in different ring systems, each system containing at least one hetero ring

Definitions

  • ELECTROPHOTOGRAPHIC MATERIAL 3 Sheets-Sheet 3 WAVELENGTH (rn u) COMPOUND 103 WAVELENGTH COMPOUND l u WAVELENGTH m l) COMPOUND 122 INVENTORS YOSHINOBU MURAKAMI YO HASEGAWA KAZUHISA MORIMOTO BY MM'EWM ATTORNEYS United States Patent 3,712,811 ELECTROPHOTOGRAPHIC MATERIAL Yoshinobu Murakami, Osaka, Yo Hasegawa, Suita, and
  • B represents a radical selected from the group consisting of and R Ru R! ACE ⁇
  • Compounds falling under the latter general formula include such compounds as 2-phenyl-4-[(2-phenyl-4-benzopyranylidene)benzylJ-benzopyrylium perchlorate and 2,3- phenyl 4 [(2-phenyl-4"benzopyranylidene)benzyl]-6- methylbenzopyrylium perchlorate.
  • This invention relates to novel light-sensitive layers and more particularly to electrophotographic light-sensitive polymer layers.
  • V'arious light-sensitive layers are well known in the electrophotographic art for making copies of documents, drawings, transparencies, etc. These layers contain organic photocondnctive compounds, such as poly-N- vinylcarbazole, brominated poly-N-vinylcarbazoles, polyacenaphthylene, etc. These layers are non-conductors of electricity before exposure and become electrical conductors upon exposure.
  • the photocondnctive material has a high photoconductivity in the long wavelength region of the visible spectrum.
  • Such a photocondnctive material makes it possible for the electrophotograph art to employ inexpensive and convenient light sources such as incandescent lamps in a reduced exposure time and to reproduce colored pictures.
  • the photoconductive materials mentioned above however, have usually a low photoconductivity and spectrum characteristics sensitive to the short wavelength region of the exposure light and do not satisfy entirely the above requiremeat.
  • sensitizer can improve photoconductivity and spectrum characteristics of the above photocondnctive compounds.
  • Conventional sensitizers are dyestuif compounds, such as triarylmethane dyes, xanthene dyes, triazine dyes or acridine dyes, but the conventional sensitizers are not entirely satisfactory to improve the photoconductivity and the spectrum characteristics of the available photocondnctive compounds.
  • the electrophotographic art requires a high electric resistance of photoconductive materials in the dark.
  • Conventional sensitizers are apt to increase the dark conductivity whereas they promote the photoconductivity.
  • a high dark conductivity of photocondnctive materials is not desirable because it results in a loss of the applied electrostatic charge in the dark.
  • An object of the invention is to provide electrophotographic materials having a high photoconductivity and spectrum characteristics sensitive to a long wavelength region of the visible spectrum.
  • Another object of the invention is to provide electrophotographic materials having a high electric resistance in the dark.
  • FIG. 1 represents the wedge spectrogram for an electrophotographic material coated with an unsensitized solution of 10 weight percent of brominated poly-N-vinylcarbazole in chlorobenzene.
  • FIG. 2 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-(a-phenyl-p-methoxystyryl) 4- (2'-phenyl-4'-benzopyranylidene) -methyl] benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
  • FIG. 3 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-styryl-3-phenyl-4- (2'-styryl-4'-benzopyranylidene methyl] -6-methyl benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
  • FIG. 4 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-p-methoxystyryl-4- [(2' a phenyl-p-methoxystyryl-4'-benzopyranylidene) methyl]benzopyrylium perchlorate, the brominated poly- N-vinylcarbazole being dissolved. in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
  • FIG. 5 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-p-methoxystyryl-4-[(2'- phenyl-4'-benzothiopyranylidene -rnethyl] benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
  • FIG. 6 represents the wedge spectrogram for an electrophotograph material coated with a solution containing 10 weight percent of brominated poly-N-vinyl carbazole sensi- 3 tized with 0.04 weight percent of 2-[2'-phenyl-4'-benzopyranylidene)methy1] 3-phenylbenzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four parts of chlorobenzene and one weight part of dichloroethane.
  • FIG. 7 represents the wedge spectrogram for an electrophotographic material coated with a solution containing weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-[ (4'-'benzothiopyranylidene)methyl]-3-phenylbenzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
  • FIG. 8 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-[2'-a-phenyl-pmethoxystyryl-4'-benz0pyranylidene)methyl] 3 phenylbenzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
  • FIG. 9 represents the Wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-[(2'-phenyl-4'- benzothiopyranylidene)methyl]-3-phenyl benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
  • the new sensitizer, according to the present invention has the following formula:
  • R is hydrogen, phenyl or an ethenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxystyryl, m-phenylstyryl, a-phenyl-pmethoxystyryl, fl-furyl(a')ethenyl and a-phenyl-p-furyl (ot' ethenyl;
  • R is hydrogen or phenyl
  • R is hydrogen, methyl or phenyl
  • R is hydrogen or phenyl
  • R is hydrogen, phenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxystyryl, a-phenyl-p-methoxystyryl, ,B-furyKa') ethenyl and a-phenyl-fi-furyl(a)ethenyl;
  • R is hydrogen or phenyl
  • R is hydrogen, methyl or phenyl
  • R is hydrogen or phenyl
  • anion is anionic function selected from the group consisting of perchlorate, fiuoroborate, chloroferrate, chlorozincate and nitrate;
  • X is oxygen or sulfur atom.
  • the sensitizers having the formula above mentioned are prepared by the following chemical Equation A or B.
  • Equation B 2-[(4'-benzopyranylidene)- methylJbenzopyrylium derivative (V) is obtained by an addition reaction of 4-methoxybenzopyrylium o-nitrobenzene sulfonate (I) with a benzopyrylium salt (IV) in an acetic anhydride solution.
  • the benzopyrylium salt has an active methyl radical.
  • 600 and 680 600 and 720. 550 and 700. 650 and 695.
  • pyrylium salts with reference to exemplary compounds. 5 .5 grams of 2 (a phenyl p methoxystyryl)-4methyl- The details of the preparation of other compounds will be benzopyrylium perchlorate and 5.5 grams of 2-phenyl4- apparent to the skilled in the art from the preceding dismethoxybenzopyrylium o-nitrobenzene sulfonate are disclosure and the following illustrative examples of prepasolved in 150 milliliters of acetic anhydride to a solution. ration methods of various compounds according to the The solution is then refluxed for 15 minutes and poured invention: into 900 millilters of 10 weight percent p-erchloric acid.
  • g are 5.5 grams of 2-phenyl-4-methoxybenzopyrylium o-nitrodried to obtain 5.5 grams (theoretical yield 69%) of benzene sulfonate, which is obtained from flavone and blue crystals having melting Point of to methyl omitmbenzenesulfonate, and 5 grams of 2 pheny1
  • z-(u-phenyl-pmilliliters of acetic anhydride to a solution.
  • 2-(3,4' dirnethoxystyryl) 4 methoxybenzopyrylium o-nitrobenzenesulfonate (melting point 211 to 213 C.) is obtained from a reaction of 2-(3',4'dimethoxystyryl) chromone and methyl o-nitrobenzene sulfonate.
  • 6.5 grams of 2 (3,4 dimethoxystyryl)-4-methoxybenzopyrylium o-nitrobenzenesulfonate and 4.5 grams of 2-p-methoxystyryl-4-methylbenzopyrylium perchlorate are dissolved in milliliters of acetic anhydride to a solution. The solution is heated at 100 C. for 100 minutes.
  • the compounds listed in Table 1 are sensitizing agents which can improve the photoconductivity and the spectrum characteristics of photoconductive polymeric compounds such as poly-N-vinylcarbazole, brominated poly-N-vinylcarbazoles, polyacenaphthylene, etc. These polymers, except brominated poly-N-vinylcarbazoles, are prepared in a per se well known method.
  • the brominated poly-N-vinylcarbazole can be prepared by the following method: To the solution of grams of poly-N-vinylcarbazole in 450 milliliters of chlorobenzene, there are added 18.44 grams of -N-bromosuccinimide and 0.173 gram of benzoyl peroxide. The mixture is heated at 80 C. for 2 hours while being stirred thoroughly and is poured into methanol to obtain a white polymer. The polymer is dissolved in chlorobenzene and again poured into methanol for purification. The pure polymer thus obtained as a precipitate exhibits upon elementary analysis a halogen content of 29.87 weight percent which approximates the value calculated, i.e.
  • the novel sensitizer comprising at least one compound from the group listed in Table 1 is dissolved in a suitable solvent, such as dichloroethane, methylene chloride, chloroform, or a combination thereof, and is added to the solution of the photoconductive polymer described above.
  • a suitable solvent such as dichloroethane, methylene chloride, chloroform, or a combination thereof.
  • the preferable amount of the sensitizer added is from 0.01 to 3.0 weight parts in connection with 100 weight parts of the photoconductive polymer.
  • the amount thereof is from 0.1 to 2.0 weight parts in connection with 100 weight parts of the photoconductive polymer.
  • Operable solvents are benzene, toluene, chlorobenzene, dioxane, methylene chloride, dichloroethane and combinations thereof.
  • Said solution may be incorporated with suitable plasticizers and/or organic colloids for improving the flexibility and strength of the photoconductive polymer.
  • Operable plasticizers are as follows: chlorinated diphenyl, dimethyl phthalate, diethyl phthalate and octyl phthalate.
  • Operable organic colloids are as follows: natural and synthetic resins, e.g. phenol resin, phenol resin modified with resin, polyvinyl acetal, polyvinyl butyral, polyvinyl cinnamate, polycarbonate resin.
  • Operable materials for electroconductive supports may be made of any materials which satisfy the requirement of the electrophotographic art, e.g. metal plate or glass plate having NESA coating, plate or foil made of electrically conductive resin or coated with evaporated thin metal layer.
  • the transparent support can produce a transparent electrophotographic plate, foil or film. After an electrostatic charge has been applied, i.e. after the layer has been charged positively or negatively by means of a corona discharge, the layer becomes light sensitive.
  • the reproducton of images by the electrophotographic method is carried out as follows: when the photoconductive layer has been charged by means of a corona discharge apparatus, the support with the sensitized layer is exposed to light under a master and is then dusted over in a per se known manner with a resin powder colored with carbon black. The image that now becomes visible can easily be wiped off. It can also be fixed by heating at about C. From positive masters, positive images characterized by good contrast are produced.
  • EXAMPLE 1 1 gram of polyacenaphthylene and 0.6 gram of, as a plasticiser, chlorinated diphenyl (commercially available as Kanechlor), are dissolved in 8 milliliters of chlorobenzene. To the solution are added 0.5 milliliter of dichloroethane containing 0.006 gram of a sensitizer corresponding to compound number listed in Table 1. The solution is applied to an aluminum plate by means of whirler coating and is dried to form a layer of 7,111 in thickness. After said aluminum plate provided with the layer is charged negatively by means of corona discharge with a charging device maintained at approximately 6000 volts in the dark, it is placed under a positive master and is exposed to a 100 w.
  • chlorinated diphenyl commercially available as Kanechlor
  • This developer consists of toner and carrier.
  • the toner consists of low melting point polystyrene, colophony and carbon black.
  • the toner is mixed with a carrier substance such that the toner becomes triboelectrically charged with a charge opposite to that produced on the plate. A positive image is produced and is fixed by slight heating.
  • Table 2 there are shown the optimum amounts of exposure in lux-second units.
  • EXAMPLE 3 1 gram of brominated poly-N-vinylcarbazole (monobromo-substituted product), 0.5 gram of polycarbonate resin (commercially available as Panlite-C), 0.3 gram of chlorinated diphenyl (commercially available as Kanechlor) and 0.002 gram of sensitizer listed in Table 1 are dissolved in a mixed-solvent of 8 milliliters of chlorobenzene and 2 milliliters of dichloroethane. This solution is applied to an aluminum plate by means of a blade coating and dried to form a layer of 14 2 in thickness. On this support, electrophotographic images are produced in the same way as that described in Example 1. Table 4 shows the optimum amounts of exposure in lux-second units to reproduce exactly the original images.
  • A11 electrophotographic material comprising a conductive support layer and photoconductive insulating layer, the latter comprising a combination of a photoconductive polymeric compound and a sensitizing amount of a sensitizer having the following formula:
  • anion- R is hydrogen, phenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxy-styryl, a-phenylstyryl, 0a phenyl pmethoxystyryl, fl-furyl (a)ethenyl and a-phenyl-fl tfuryl(a) ethenyl;
  • R is hydrogen or phenyl
  • R is hydrogen, methyl or phenyl
  • R is hydrogen or phenyl
  • R is hydrogen, phenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxy-styryl, a-phenyl-p-methoxystyryl, flfuryl(u')ethenyl and a-phenyl-p-turyl(a')ethenyl;
  • R is hydrogen or phenyl
  • R is hydrogen or phenyl
  • the anion is an anionic function selected from the group consisting of perchlorate, fluoroborate, chloroferrate, chlorozincate and nitrate;
  • X is oxygen or a sulfur atom
  • said photoconductive polymeric compound comprising at least one compound selected from the group consisting of poly-N-vinylcarbazole, brominated poly-1 vinylcarbazole and polyacenaphthylene.
  • sensitizer comprises at least one compound selected from the group consisting of 2- a-phenyl-p-methoxystryl) -4- 2-phenyl-4'benzopyranylidene)methyl] benzopyrylium perchlorate,
  • An electrophotographic material accordingto claim 1, wherein said combination comprises Weight parts of photoconductive polymeric compound and 0.01 to 3.0 weight parts of sensitizer.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Plural Heterocyclic Compounds (AREA)
  • Developing Agents For Electrophotography (AREA)

Abstract

AN ELECTROPHOTOGRAPHIC MATERIAL IS PROVED HEREIN WHICH COMPRISES A CONDUCTIVE SUPPORT LAYER AND A PHOTOCONDUCTIVE INSULATING LAYER, THE LATTER LAYER COMPRISING A PHOTOCONDUCTIVE POLYMERIC COMPOUND SUCH AS POLY-NVINYLCARBAZOLE, AND A SENSITIZER HAVING THE FOLLOWING GENERAL FORMULA

(X<((R1-)C=C(-R2)-C(=C(-R4)(-B))-(5-R3-1,2-PHENYLENE)-))+

ANION (-)

WHEREIN B REPRESENTS A RADICAL SELECTED FROM THE GROUP CONSISTING OF

2-R5,3-R6,6-R7-BENZOPYR-3-YLIUM AND X<(=C(-)-C(-R8)=C(

4-(H3C-O-)PHENYL)-(1,2-PHENYLENE)-)

COMPOUNDS FALLING UNDER THE LATTER GENERAL FORMULA INCLUDE SUCH COMPOUNDS AS 2-PHENYL-4- (2''-PHENYL-4''-BENZOPYRANYLIDENE) BENZYL!-BENZOPYRYLIUM PERCHLORATE AND 2,3PHENYL-4- (2''-PHENYL-4''BENZOPYRANYLIDENE)BENZYL!-6METHYLBENZOPYRYLIUM PERCHLORATE.

Description

Jam 23, 1973 YOSHINOBU MURAKAMI ETAL 3,7
ELECTROPHOTOGRAPHI C MATER IAL Filed March 5, 1971 3 Sheets-Sheet 1 FIG] WAVELENGTH FIG.2
WAVELENGTH (my) COMPOUND 7 FIG.3
INVENTORS YOSHINOBU MURAKAMI YO HASEGAWA KAZUHISA MORIMOTO BY Q 12 ATTORNEYS J8!!- 1973 YOSHINOBU MURAKAMI ETAL 3,712,811
ELECTROPHOTOGRAPHIC MATERIAL Filed March 5, 1971 3 Sheets-Sheet 2 WAVELENGTH (m u) COMPOUND 57 -FIG.5
WAVELENGTH (m COMPOUND 83 WAVELENGTH (m COMPOUND 92 INVENTORS YOSHINOBU MURAKAMI YO HASEGAWA KAZUHISA MOF?! MOj ZO' BY Mu 1%- 2M ATTORNEYS Jan. 23, 1973 Filed March 5, 1971 FIG] YOSHINOBU MURAKAMI ETAL 3,712,811
ELECTROPHOTOGRAPHIC MATERIAL 3 Sheets-Sheet 3 WAVELENGTH (rn u) COMPOUND 103 WAVELENGTH COMPOUND l u WAVELENGTH m l) COMPOUND 122 INVENTORS YOSHINOBU MURAKAMI YO HASEGAWA KAZUHISA MORIMOTO BY MM'EWM ATTORNEYS United States Patent 3,712,811 ELECTROPHOTOGRAPHIC MATERIAL Yoshinobu Murakami, Osaka, Yo Hasegawa, Suita, and
Kazuhisa Morimoto, Settsu, Japan, assignors to Matsushita Electric Industrial Company Limited, Osaka,
Japan Filed Mar. 5, 1971, Ser. No. 121,508 Claims priority, application Japan, Mar. 13, 1970, 45/21,766, 45/21,767
Int. Cl. G03g 5/06 US. Cl. 961.6 3 Claims eral formula fiT V anion- LB. l;
wherein B represents a radical selected from the group consisting of and R Ru R! ACE} Compounds falling under the latter general formula include such compounds as 2-phenyl-4-[(2-phenyl-4-benzopyranylidene)benzylJ-benzopyrylium perchlorate and 2,3- phenyl 4 [(2-phenyl-4"benzopyranylidene)benzyl]-6- methylbenzopyrylium perchlorate.
This invention relates to novel light-sensitive layers and more particularly to electrophotographic light-sensitive polymer layers.
V'arious light-sensitive layers are well known in the electrophotographic art for making copies of documents, drawings, transparencies, etc. These layers contain organic photocondnctive compounds, such as poly-N- vinylcarbazole, brominated poly-N-vinylcarbazoles, polyacenaphthylene, etc. These layers are non-conductors of electricity before exposure and become electrical conductors upon exposure.
It is necessary for the electrophotographic art that the photocondnctive material has a high photoconductivity in the long wavelength region of the visible spectrum. Such a photocondnctive material makes it possible for the electrophotograph art to employ inexpensive and convenient light sources such as incandescent lamps in a reduced exposure time and to reproduce colored pictures. The photoconductive materials mentioned above, however, have usually a low photoconductivity and spectrum characteristics sensitive to the short wavelength region of the exposure light and do not satisfy entirely the above requiremeat.
It is known that an addition of a so-called sensitizer can improve photoconductivity and spectrum characteristics of the above photocondnctive compounds. Conventional sensitizers are dyestuif compounds, such as triarylmethane dyes, xanthene dyes, triazine dyes or acridine dyes, but the conventional sensitizers are not entirely satisfactory to improve the photoconductivity and the spectrum characteristics of the available photocondnctive compounds.
In addition to the high photoconductivity and spectrum characteristics sensitive to visible light, the electrophotographic art requires a high electric resistance of photoconductive materials in the dark. Conventional sensitizers are apt to increase the dark conductivity whereas they promote the photoconductivity. A high dark conductivity of photocondnctive materials is not desirable because it results in a loss of the applied electrostatic charge in the dark.
An object of the invention is to provide electrophotographic materials having a high photoconductivity and spectrum characteristics sensitive to a long wavelength region of the visible spectrum.
Another object of the invention is to provide electrophotographic materials having a high electric resistance in the dark.
These and other objects are accomplished by adding a new sensitizer shown hereinafter to a photocondnctive polymeric compound such as poly-N-vinylcarbazole, brominated poly-N-vinyl-carbazole or polyacenaphthylene, as a light-sensitive film-forming composition.
The invention is further explained in the following description with reference to the accompanying drawings wherein:
FIG. 1 represents the wedge spectrogram for an electrophotographic material coated with an unsensitized solution of 10 weight percent of brominated poly-N-vinylcarbazole in chlorobenzene.
FIG. 2 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-(a-phenyl-p-methoxystyryl) 4- (2'-phenyl-4'-benzopyranylidene) -methyl] benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
FIG. 3 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-styryl-3-phenyl-4- (2'-styryl-4'-benzopyranylidene methyl] -6-methyl benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
FIG. 4 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-p-methoxystyryl-4- [(2' a phenyl-p-methoxystyryl-4'-benzopyranylidene) methyl]benzopyrylium perchlorate, the brominated poly- N-vinylcarbazole being dissolved. in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
FIG. 5 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-p-methoxystyryl-4-[(2'- phenyl-4'-benzothiopyranylidene -rnethyl] benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
FIG. 6 represents the wedge spectrogram for an electrophotograph material coated with a solution containing 10 weight percent of brominated poly-N-vinyl carbazole sensi- 3 tized with 0.04 weight percent of 2-[2'-phenyl-4'-benzopyranylidene)methy1] 3-phenylbenzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four parts of chlorobenzene and one weight part of dichloroethane.
FIG. 7 represents the wedge spectrogram for an electrophotographic material coated with a solution containing weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-[ (4'-'benzothiopyranylidene)methyl]-3-phenylbenzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
FIG. 8 represents the wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-[2'-a-phenyl-pmethoxystyryl-4'-benz0pyranylidene)methyl] 3 phenylbenzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
FIG. 9 represents the Wedge spectrogram for an electrophotographic material coated with a solution containing 10 weight percent of brominated poly-N-vinylcarbazole sensitized with 0.04 weight percent of 2-[(2'-phenyl-4'- benzothiopyranylidene)methyl]-3-phenyl benzopyrylium perchlorate, the brominated poly-N-vinylcarbazole being dissolved in a solvent of four weight parts of chlorobenzene and one weight part of dichloroethane.
The new sensitizer, according to the present invention has the following formula:
X Rl R3 Anionwhere B represents a radical selected from the group consisting of,
AGE:
R is hydrogen, phenyl or an ethenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxystyryl, m-phenylstyryl, a-phenyl-pmethoxystyryl, fl-furyl(a')ethenyl and a-phenyl-p-furyl (ot' ethenyl;
R is hydrogen or phenyl;
R is hydrogen, methyl or phenyl;
R is hydrogen or phenyl;
R is hydrogen, phenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxystyryl, a-phenyl-p-methoxystyryl, ,B-furyKa') ethenyl and a-phenyl-fi-furyl(a)ethenyl;
R is hydrogen or phenyl;
R is hydrogen, methyl or phenyl;
R is hydrogen or phenyl;
the anion is anionic function selected from the group consisting of perchlorate, fiuoroborate, chloroferrate, chlorozincate and nitrate; and
X is oxygen or sulfur atom.
The sensitizers having the formula above mentioned are prepared by the following chemical Equation A or B.
In the case of Equation A, 4-[(4-benzopyranylidene)- methyl]benzopyrylium derivative (III) is obtained by an addition reaction of 4-methoxybenzopyrylium o-nitrobenzene sulfonate (I) with a benzopyrylium salt (II) in an acetic anhydride solution. The benzopyrylium salt has an active methyl or methylene radical.
In the case of Equation B, 2-[(4'-benzopyranylidene)- methylJbenzopyrylium derivative (V) is obtained by an addition reaction of 4-methoxybenzopyrylium o-nitrobenzene sulfonate (I) with a benzopyrylium salt (IV) in an acetic anhydride solution. The benzopyrylium salt has an active methyl radical.
EQUATION A anion- I anion- R1 \/-R| R3 R1 iH, %-R4 (III) EQUATION B O X 4, on, R,
auionanion- R5 R3 R1 Rs YE- 8 9 TABLE lcontinued Compound number: Name of Compound 1 13. 2- (2-p-methoxystyryl-3 ',6'-diphenyl-4'-benzopyranylidene) methyl] -3-phenylbenzopyrylium perchlorate 2- (2'-3 ",4"-dimethoxystyryl-3 ,6-diphenyl-4'- benzopyranylidene methyl] 3-phenylb enzopyrylium perchlorate 2- (2-p-methoxystyryl-3'-phenyl-6'-methyl-4'- benzopyranylidene) methyl] benzopyrylium perchlorate 2-[ (2'-p-methoxystyryl-3 '-phenyl-6 '-methyl-4'- benzopyranylidene) methyl] -3-pheny1benzopyrylium perchlorate 2- (2'-3 ",4"-dimethoxystyryl-3 '-pheny1-6'-methyl- 4'-benzopyranylidene) methyl] benzopyrylium perchlorate 2-[ (2'-3 ,4"-dimethoxystyryl-3-phenyl-6'-methyl- 4--benzopyranylidene)methyl] -3-phenylbenzopyrylium perchlorate 2- (2'-p-furyl( a ethenyl-3 '-phenyl-6'-methyl-4- benzopyranylidene )methyl] benzopyrylium perchlorate 2-[ (2'-B-furyl (11 ethenyl-3'-phenyl-6 -methyl-4'- benzopyranylidene) methyl] -3-phenylbenzopyrylium perchlorate 2-[ (2'-phenyl-4'-benzothiopyranylidene) methyl] benzopyrylium perchlorate 2- 2'-phenyl-4'-b enzothiopyr-anylidene) methyl]- B-phenylbenzopyrylium perchlorate 2-[ (2'-phenyl-4'-benzopyranylidene) methyl] -4-pmethoxyphenylbenzothiopyrylium perchlorate 2- 2-phenyl-4'-benzopyranylidene) methyl] -3- phenyl-4-p-methoxyphenylbenzopyrylium perchlorate 2- (2-a-phenyl-p-rnethoxystyry1-4'-benzopyranylidene methyl] -4-p-methoxyphenylbenzothiopyrylium perchlorate 2- (2-a-phenyl-p-methoxystyryl-4'-b enzopyranylidene methyl] -3-phenyl-4-p-methoxyphenylbenzothiopyrylium perchlorate 2-[ (2'-phenyl-4-benzothi0pyrany1idene methyl] 4-p-methoxyphenylbenzothiopyrylium perchlorate 2-[ (2'-pheny1-4'-benzothiopyranylidene methyl] 3-phenyl-4-p-methoxyphenylbenzothiopyrylium perchlorate Table 2 lists additional information on the absorption maximum in dichloroethane and melting point of the novel compounds according to the invention.
TABLE 2 Absorption maximum in dichloroethane (m 415 and 710. 430 and 720. 410 and 630. 635
490 and 575. 575 and 660. 500 and 610. 490 and 670. 157160 550 and 670. 103-105 610.
430 and 700. 420 and 730. 420 and 650. 500 and 600. 495 and 710. 135440 580.
555. 420 and 730. 415 and 730. 410 and 700. 500 and 600. 485. 170-175 505.
Compound number TABLE 2--Continued Compound number Melting pointv Absorption maximum in dichloroethane (my) 560. 500 and 590.
- 660 and 710.
410 and 650. 430 and 690. 420 and 700.
1 550 and 650.
59 495 and 600 610, 650 and 700. 415 and 650.
1 425 and 700.
415 and 730. 660.
540 and 600. 660 and 710. 580 and 720. 415 and 720. 425 and 720.
0. 490 and 580. 600 and 720. 610 and 660. 480 and 740. 495 and 580. 590 and 700. 550 and 750. 420 and 680. 555 and 680.
570. 585 and 690. 570.
530 and 690.
- 590. 500 and 600.
570 and 760. 495
65051111 700. 500 and 710.
590. 495 and 640. 550. 415 and 720.
640 and 700.
410 and 745. 425 and 730.
600 and 680. 600 and 720. 550 and 700. 650 and 695.
500 and 610.
500 and 610.
500 and 610.
575 and 675. 575 and 675. 575 and 675.
620 and 690.
525 and 560.
630 and 690.
610 and 690.
' 580111111 690. 565 and 620. 550 and 635.
570 and 610. 570 and 610.
. 570 and 610. 580 and 630.
600 and 645.
' 570 and 620.
600. 665 and 600.
. 570 and 610.
590. 565 and 605.
615 and 675.
' 559 and e57.
589 and 663. 656. 660.
12 The following description will explain a practical (b) 2 (a phenyl p methoxystyryl) 4 [(2'-phenylmethod for making benzopyranylidene-methylbenzo- 4 benzopyranylidene)methyl]benzopyryliurn perpyrylium salts or benzothiopyranylidene-methylbenzochlorate (compound number 7) (Lee.
Q g C10;
pyrylium salts with reference to exemplary compounds. 5 .5 grams of 2 (a phenyl p methoxystyryl)-4methyl- The details of the preparation of other compounds will be benzopyrylium perchlorate and 5.5 grams of 2-phenyl4- apparent to the skilled in the art from the preceding dismethoxybenzopyrylium o-nitrobenzene sulfonate are disclosure and the following illustrative examples of prepasolved in 150 milliliters of acetic anhydride to a solution. ration methods of various compounds according to the The solution is then refluxed for 15 minutes and poured invention: into 900 millilters of 10 weight percent p-erchloric acid.
The solution is filtered to obtain a precipitate. The pre- (a) 2-phenyl-4-[(2'-phenyl-4'-benzopy yl den y l cipitate is reprecipitated with dichloroethane ether. Prebenzopyrylium perchlorate (compound number 1) cipitated crystals are filtered 01f, washed with ether and Q Q AW ,0 Q tl. g are 5.5 grams of 2-phenyl-4-methoxybenzopyrylium o-nitrodried to obtain 5.5 grams (theoretical yield 69%) of benzene sulfonate, which is obtained from flavone and blue crystals having melting Point of to methyl omitmbenzenesulfonate, and 5 grams of 2 pheny1 In the procedure above mentioned the solution is poured into an ether solution of B=F -O(C H instead of 10 4-benzylbenzopyryl1um perchlorate are dlssolved 1n 150 weight percent perchloric acid. In hi case z-(u-phenyl-pmilliliters of acetic anhydride to a solution. The solution methoxystyryl) 4 [(2, phenyl benzopyranylidene) is then refluxed for 15 minutes and poured into 900 millimethyl]benzopyrylium fluoroborate (compound number liters of 10 weight percent perchloric acid. The solution is Obtained- In the Procedllffi When the So ution is is filtered to obtain a precipitate. The precipitate is dried Pour? into a 10 Weight Percent Zinc chloride aqueous solutlon, 2 (or phenyl-p-methoxystyryl)-4-[(2'-phenyland dissolved again n drchloroethan to a solution. For benzopyranylidene)methyl]benzopyrylium Chlorm purrficatlon the solution is poured into ether. Precipitated 5 Zincate (compound number 90) is obtained crystals are filtered off, washed wrth ether and drred to (c) 2 p methoxystyryl 3 Obtaln 4 grams (theoretlcal Yleld of green crystals benzopyranylidene)methyl] 6 methylbenzopyrylium having a melting point of to 139 C. perchlorate (compound number 18) 2 styryl 4 methoxybenzopyrylium o nitrobenzenesulfonate (melting point, 155 to 157 C.) is obtained by a reaction of 2-styrylchromone and methyl o-nitrobenzenesulfonate in dry benzene at 50 C. for 24 hours. According to the same reaction as shown in procedure (a), 2 styryl 4 methoxybenzopyrylium o nitrobenzenesulfonate reacts with 2-p-methoxystyryl-3-phenyl-4,6-dimethylbenzopyrylium perchlorate to obtain 2-p-methoxystyryl 3 phenyl 4 [(2 styryl-4'-benzopyranylidene) methyl] 6 methylbenzopyrylium perchlorate crystals which have a color of reddish violet in dichloroethane and have a melting point of 159 to 162 C. The product is obtained in 73% yield.
(d) 2 (a phenyl p methoxystyryl)-4-[(4'-benzopyranylidene)methyl]benzopyrylium perchlorate (compound number 22) 4 methoxybenzopyrylium o nitrobenzenesulfonate reacts with 2 (a phenyl p methoxystyryl)-4-rnethyl] benzopyrylium perchlorate to 2 (a phenyl p methoxystyryl) 4 [(4-benzopyranylidene)methyH-benzopyrylium perchlorate in the same procedure as the procedure (a). The crystals have a color of violet in dichloroethane and a melting point of 174 to 178 C. The prodnet is obtained in 95% yield.
(e) 2 p methoxystyryl 4 [(2 3",4 dimethoxystyryl 4 benzopyranylidene)methyHbenzopyrylium perchlorate (compound number 42) OOH: NO:
2-(3,4' dirnethoxystyryl) 4 methoxybenzopyrylium o-nitrobenzenesulfonate (melting point 211 to 213 C.) is obtained from a reaction of 2-(3',4'dimethoxystyryl) chromone and methyl o-nitrobenzene sulfonate. 6.5 grams of 2 (3,4 dimethoxystyryl)-4-methoxybenzopyrylium o-nitrobenzenesulfonate and 4.5 grams of 2-p-methoxystyryl-4-methylbenzopyrylium perchlorate are dissolved in milliliters of acetic anhydride to a solution. The solution is heated at 100 C. for 100 minutes. After cooling the solution is poured into 900 milliliters of 10 weight percent perchloric acid. Precipitates are filtered oif and dried. For purification, reprecipitation is made using dichloroethane and ether. 3.2 grams of product is obtained in 41% yield. The product has a color of dark violet in dichloroethane and a melting point of to 181 C.
C10 r Ha 2-phenyl-4-methoxybenzothiopyrylium o-nitrobenzenesulfonate is obtained from thioflavone and methyl o-nitrobenzenesulfonate. As the same procedure as procedure r (e), the product is obtained in 62% yield. The product has a color of reddish violet in dichloroethane and melting point of 170 to 177 C.
(h) 2 [(2 phenyl 4' benzopyranylidene)methyl]-3- phenylbenzopyrylium perchlorate (compound number 60 16 Q OH=CH-OOH: h to CH Q @a =CH-OCH1 5.5 grams of 2 phenyl 4 methoxybenzopyrylium o-nitrobenzenesulfonate, which is obtained from flavone and methyl o-nitrobenzenesulfonate, and 4 grams of 2-methyl-3-phenylbenzopyry1ium perchlorate are dissolved in 150 milliliters of acetic anhydride to a solution. The solution is heated at 100 C. for 15 minutes. After cooling the solution is poured into 900 milliliters of 10 weight percent perchloric acid. Precipitated product is filtered ofi and dried. For purification, reprecipitation is made using dichloroethane and ether. The product has a color of blue in dichloroethane and a melting point of OCHa 128 to 134 C. The product yields 3 grams (theoretical yield 46%). Compound number 93 (fiuoborate), compound number 94 (chloroferrate) or compound number 95 (nitrate) is obtained using either solution of borontrifluoride etherate, aqueous solution of ferric chloride or diluted nitric acid respectively instead of 10 weight percent perchloriic acid.
. C10 HE C 10 4 OCH;
2 (a-phenyl-p-methoxystyryl) 4 methoxybenzopyrylium o-nitrobenzenesulfonate, which is obtained from 2 (a phenyl p methoxystyryl)chromone and methyl o-nitrobenzenesulfonate, reacts with 2-methyl-3-phenylbenzopyrylium perchlorate in the same procedure as procedure (h). The reaction product yields in 43%. The product has a color of violet in dichloroethane and a melting point of 158 to 163 C.
It has been discovered according to the invention the compounds listed in Table 1 are sensitizing agents which can improve the photoconductivity and the spectrum characteristics of photoconductive polymeric compounds such as poly-N-vinylcarbazole, brominated poly-N-vinylcarbazoles, polyacenaphthylene, etc. These polymers, except brominated poly-N-vinylcarbazoles, are prepared in a per se well known method. The brominated poly-N-vinylcarbazole can be prepared by the following method: To the solution of grams of poly-N-vinylcarbazole in 450 milliliters of chlorobenzene, there are added 18.44 grams of -N-bromosuccinimide and 0.173 gram of benzoyl peroxide. The mixture is heated at 80 C. for 2 hours while being stirred thoroughly and is poured into methanol to obtain a white polymer. The polymer is dissolved in chlorobenzene and again poured into methanol for purification. The pure polymer thus obtained as a precipitate exhibits upon elementary analysis a halogen content of 29.87 weight percent which approximates the value calculated, i.e. 29.44 weight percent of the monobromosubstituted product from poly-N-vinylcarbazole. This indicates that the polymer obtained is a monobromosubstituted product. The degree of bromination varies from 50 mole percent to 200 mole percent according to reaction conditions.
The novel sensitizer comprising at least one compound from the group listed in Table 1 is dissolved in a suitable solvent, such as dichloroethane, methylene chloride, chloroform, or a combination thereof, and is added to the solution of the photoconductive polymer described above. The preferable amount of the sensitizer added is from 0.01 to 3.0 weight parts in connection with 100 weight parts of the photoconductive polymer. Advantageously, the amount thereof is from 0.1 to 2.0 weight parts in connection with 100 weight parts of the photoconductive polymer.
For the preparation of the photoconductive insulating layer, a said solution of the photoconductive polymer and the sensitizer in a suitable solvent is applied to the elec- 18 troconductive support in per se usual manner, for example, by spraying, by means of bladed coating, by means of whirler coating, etc., and then dried so as to produce 0 o=cn -oom cm 11102 a homogeneous photoconductive insulating layer on the electroconductive support. Operable solvents are benzene, toluene, chlorobenzene, dioxane, methylene chloride, dichloroethane and combinations thereof. Said solution may be incorporated with suitable plasticizers and/or organic colloids for improving the flexibility and strength of the photoconductive polymer. Operable plasticizers are as follows: chlorinated diphenyl, dimethyl phthalate, diethyl phthalate and octyl phthalate. Operable organic colloids are as follows: natural and synthetic resins, e.g. phenol resin, phenol resin modified with resin, polyvinyl acetal, polyvinyl butyral, polyvinyl cinnamate, polycarbonate resin. Operable materials for electroconductive supports may be made of any materials which satisfy the requirement of the electrophotographic art, e.g. metal plate or glass plate having NESA coating, plate or foil made of electrically conductive resin or coated with evaporated thin metal layer. If paper is to be used as a support for the photoconductive layer, pretreatment of the paper against penetration of the coating solution is advisable. The transparent support can produce a transparent electrophotographic plate, foil or film. After an electrostatic charge has been applied, i.e. after the layer has been charged positively or negatively by means of a corona discharge, the layer becomes light sensitive.
The reproducton of images by the electrophotographic method is carried out as follows: when the photoconductive layer has been charged by means of a corona discharge apparatus, the support with the sensitized layer is exposed to light under a master and is then dusted over in a per se known manner with a resin powder colored with carbon black. The image that now becomes visible can easily be wiped off. It can also be fixed by heating at about C. From positive masters, positive images characterized by good contrast are produced.
This invention is still further illustrated with reference to the following illustrative examples.
EXAMPLE 1 1 gram of polyacenaphthylene and 0.6 gram of, as a plasticiser, chlorinated diphenyl (commercially available as Kanechlor), are dissolved in 8 milliliters of chlorobenzene. To the solution are added 0.5 milliliter of dichloroethane containing 0.006 gram of a sensitizer corresponding to compound number listed in Table 1. The solution is applied to an aluminum plate by means of whirler coating and is dried to form a layer of 7,111 in thickness. After said aluminum plate provided with the layer is charged negatively by means of corona discharge with a charging device maintained at approximately 6000 volts in the dark, it is placed under a positive master and is exposed to a 100 w. tungsten lamp at an illumination of 50 luxes, and the said plate is powdered over with a developer in a per se known manner. This developer consists of toner and carrier. The toner consists of low melting point polystyrene, colophony and carbon black. The toner is mixed with a carrier substance such that the toner becomes triboelectrically charged with a charge opposite to that produced on the plate. A positive image is produced and is fixed by slight heating. In Table 2, there are shown the optimum amounts of exposure in lux-second units.
TABLE 2 Compound number: Optimum exposure (lux-sec.) None 200000 EXAMPLE 2 1 gram of poly-N-vinylcarbazole, chlorinated diphenyl (commercially available as Kanechlor) and 0.006 gram of a sensitizer, corresponding to compound number listed in Table 1, in milliliters of dichloroethane to a solution. The solution is applied to an aluminum plate by means of blade coating and is dried to form a layer of 10 in thickness. An electrophotographic image is produced in the same way as that described in Example 1. In Table 3, there are shown the optimum amounts of exposure in lux-second units to produce exactly the original images.
TABLE 3 Compound number: Optimum exposure (lux-sec.) None 20000 1 50 2 220 3 60 4 70 5 2'2 6 44 7 26 8 62 9 44 10 48 l l l 60 12 220 20 TABLE 3Continued Compound number: Optimum exposure (lux-sec.)
21 TABLE 3'-Conti uued Compound number: Optimum exposure (lux-sec.)
It is clear from Table 3 that the novel sensitizers improve the photoconductivity of poly-N-vinylcarbazole.
EXAMPLE 3 1 gram of brominated poly-N-vinylcarbazole (monobromo-substituted product), 0.5 gram of polycarbonate resin (commercially available as Panlite-C), 0.3 gram of chlorinated diphenyl (commercially available as Kanechlor) and 0.002 gram of sensitizer listed in Table 1 are dissolved in a mixed-solvent of 8 milliliters of chlorobenzene and 2 milliliters of dichloroethane. This solution is applied to an aluminum plate by means of a blade coating and dried to form a layer of 14 2 in thickness. On this support, electrophotographic images are produced in the same way as that described in Example 1. Table 4 shows the optimum amounts of exposure in lux-second units to reproduce exactly the original images.
TABLE 4 Compound number: Optimum exposure (lux-sec.)
None 800 TABLE 4Continued Compound number:
Optimum exposure (lllX-SEC.)
TABLE 4-Continued Compound number: Optimum exposure (lux-sec.)
It is clear from Table 4 and FIGS. 1 to 9 that the novel sensitizers improve the photoconductivity and the spectrum characteristics of brominated poly-N-vinylcarbazole.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will he understood that variations and modifications can be efiected Within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.
What we claim is:
1. A11 electrophotographic material comprising a conductive support layer and photoconductive insulating layer, the latter comprising a combination of a photoconductive polymeric compound and a sensitizing amount of a sensitizer having the following formula:
anion- R is hydrogen, phenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxy-styryl, a-phenylstyryl, 0a phenyl pmethoxystyryl, fl-furyl (a)ethenyl and a-phenyl-fl tfuryl(a) ethenyl;
R is hydrogen or phenyl;
R is hydrogen, methyl or phenyl;
R is hydrogen or phenyl;
R is hydrogen, phenyl or an ethenyl radical selected from the group consisting of styryl, p-methoxystyryl, 3,4-dimethoxy-styryl, a-phenyl-p-methoxystyryl, flfuryl(u')ethenyl and a-phenyl-p-turyl(a')ethenyl;
R is hydrogen or phenyl;
R is hydrogen or phenyl;
the anion is an anionic function selected from the group consisting of perchlorate, fluoroborate, chloroferrate, chlorozincate and nitrate; and
X is oxygen or a sulfur atom;
said photoconductive polymeric compound comprising at least one compound selected from the group consisting of poly-N-vinylcarbazole, brominated poly-1 vinylcarbazole and polyacenaphthylene.
2. An electrophotographic material according to claim 1, wherein said sensitizer comprises at least one compound selected from the group consisting of 2- a-phenyl-p-methoxystryl) -4- 2-phenyl-4'benzopyranylidene)methyl] benzopyrylium perchlorate,
2-p-methoxystyryl-4-[ (2'-3",4"-dimeth0xystryl-3'-phenyl- 6'-methyl-4'-benzopyranylidene)methyl]benzopyrylium perchlorate,
2-[ (2'-phenyl-4'-benzopyranylidene methyl] -3-phenyl benzopyrylium fiuoroborate,
2- (2'-phenyl-4'-benzopyranylidene methyl] -4-p-methoxyphenyl benzothiopyrylium perchlorate, and
2-[ (2-phenyl-4'-benzothiopyranylidene methyl] -4-pmethoxyphenyl benzothiopyrylium perchlorate.
3. An electrophotographic material accordingto claim 1, wherein said combination comprises Weight parts of photoconductive polymeric compound and 0.01 to 3.0 weight parts of sensitizer.
References Cited UNITED STATES PATENTS 3,617,268 11/1971 Murakarni et a1. 96-1.5 3,526,502 9/1970 M-urakami et al. 96-1.6 X 3,586,500 6/1971 Contois et al 961.6
CHARLES E. VAN HORN, Primary Examiner US. Cl. X.R. 260327 R, 345.2
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3881924A (en) * 1971-08-25 1975-05-06 Matsushita Electric Ind Co Ltd Organic photoconductive layer sensitized with trimethine compound
US3907561A (en) * 1972-10-06 1975-09-23 Ricoh Kk Pyronyl-pyrylium sensitizers for electrophotographic organic photoconductors
US3953433A (en) * 1971-06-22 1976-04-27 Ricoh Co., Ltd. Sensitizer for use in electrophotographic light-sensitive material

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NL8103419A (en) * 1981-04-01 1982-11-01 Philips Nv LINE TEST CIRCUIT FOR A SUBSCRIBER PHONE.

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3953433A (en) * 1971-06-22 1976-04-27 Ricoh Co., Ltd. Sensitizer for use in electrophotographic light-sensitive material
US3881924A (en) * 1971-08-25 1975-05-06 Matsushita Electric Ind Co Ltd Organic photoconductive layer sensitized with trimethine compound
US3907561A (en) * 1972-10-06 1975-09-23 Ricoh Kk Pyronyl-pyrylium sensitizers for electrophotographic organic photoconductors

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